1. Field of the Invention
The present invention relates to an apparatus for and method of recognizing trays in a printer, and more particularly, to an apparatus for and method of recognizing trays optionally mounted in a printer using a unique identification (ID) assigned to each tray.
2. Description of the Related Art
FIGS. 1A and 1B are block diagrams illustrating a conventional apparatus for recognizing trays in a printer. Referring to FIG. 1A, the conventional apparatus for recognizing trays includes a main frame “a” including a main controller a-1, a first option tray 1a including a first controller 1a-1 for the first option tray, a second option tray 2a including a second controller 2a-1 for the second option tray, and a third option tray 3a including a third controller 3a-1 for the third option tray. The main controller a-1 controls transmission and reception of printing data, data processing, motors, sensors, communications with the trays, and printing. The first controller 1a-1, the second controller 2a-1, and the third controller 3a-1 perform control operations to control motors and sensors required by the main controller a-1.
A serial interface 4a transmits control data required by the main controller (a-1) and necessary information. The first controller 1a-1, the second controller 2a-1, and the third controller 3a-1 have independent interface lines. In FIG. 1A, since data is transmitted and received between the main controller a-1 and the first controller 1a-1, the second controller 2a-1, and the third controller 3a-1 through the serial interface 4a, which is independently connected to each of the first, second, and third controllers 1a-1, 2a-1, and 3a-1, the main controller a-1 allocates a unique identification (ID) to each of the first, second, and third option trays 1a, 2a, and 3a and determines whether the first, second, and third option trays 1a, 2a, and 3a are connected or not. However, the apparatus in FIG. 1A has the following drawbacks. A production cost of the independent serial interface 4a is high, the structure of the serial interface 4a is complex, and the first, second, and third option trays 1a, 2a, and 3a each should be distinctive.
Referring to FIG. 1B, the conventional apparatus for recognizing trays includes a main frame “b” including a main controller (b-1), a first option tray 1b including a first controller 1b-1 and a first switch 1b-2, a second option tray 2b including a second controller 2b-1 and a second switch 2b-2, and a third option tray 3b including a third controller 3b-1 and a third switch 3b-2. The operation of each block is the same as that in FIG. 1A except the first, second, and third switches 1b-2, 2b-2, and 3b-2 manually set by the first, second, and third option trays 1b, 2b, and 3b. A serial interface 4b includes a data transmission line, such as a bus. Referring to FIG. 1B, the first, second, and third option trays 1b, 2b, and 3b recognize their own identifications (IDs) through the first, second, and third switches 1b-2, 2b-2, and 3b-2 and transmit IDs to the main controller b-1. Thus, the main controller b-1 recognizes the IDs of each of the first, second, and third option trays 1b, 2b, and 3b and determines whether or not the first, second, and third option trays 1b, 2b, and 3b are connected. However, a user should manually operate the first, second, and third switches 1b-2, 2b-2, and 3b-2. Further, if the user accidentally sets the same ID to different trays, errors occur during the operation of the printer in data transmission and reception, which may damage the trays in the printer.